Supercritical carbon dioxide microemulsions

Ohde, H Hunt, F. and Wai, C.M. (2001) Synthesis of silver and copper nanopartides in a water-in-supercritical-carbon dioxide microemulsion. Chemistry of Materials, 13 (11), 4130-4135. 

Water in supercritical carbon dioxide microemulsions spectroscopic investigation of a new environment for aqueous inorganic chemistry... 

Water in Supercritical Carbon Dioxide Microemulsions—Spectroscopic Investigation of a New Environment for Aqueous Inorganic Chemistry (Clarke et al., 1997a)... 

A potent, new solvent is evolving—a supercritical carbon dioxide microemulsion. A C02-based microemulsion is especially attractive since CO2 is very abundant, relatively inexpensive, and environmentally benign at this scale of use. Applications of this system to cleaning processes appear very promising. 

Ji M, Chen X, Wai CM, Fulton JL. Synthesizing and dispersing silver nanoparticles in a water-in supercritical carbon dioxide microemulsion. J Am Chem Soc 1999 121 2631-2632. 

Clarke MJ, Harrison KL, Johnston KP, Howdle SM. Water in supercritical carbon dioxide microemulsions spectroscopic investigation of a new environment for aqueous inorganic chemistry. J Am Chem Soc 1997 119 6399-6406. 

So far we can generate supercritical carbon dioxide microemulsions with varying mi-crostructures under a pressure of p = 220 bar. The next step is to find appropriate surfactants for an efficient solubilisation of C02 as today over 48 wt.% surfactant is required to formulate a one-phase region in the system H20/NaCl-C02-Lutensol XL70 (see Fig.ll.3).Good amphiphilic candidates with C02 -philic parts are fluorinated surfactants. Once a more efficient surfactant has been identified, the formation of microemulsions under pressure has to be studied. 

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